Safety latch for doors



April 7, 1925. 1,532,737

I A. c. DOHRMANN SAFETY LATCH FOR DOORS Filed March 13, 192;

raisin carries.

ALBERT C. DOHRMANN, OF CHICAGO, ILLINOIS.

. SAFETY LATCH nos. noons.

Application filed March 13, 1922. Serial No. 543,172.

To all whom it may concern Be it known that E, MANN. a citizen of theUnited states and a resident of the city of Chicago, in the countyofCook and State of Illinois, have invented certain new and usefulImprovements in Safety Latches for Doors, of which the following is aspecification.

This invention relates to improvements in safety latch'es for opendoors, in which the latch bar is secured and hinged to the door frameand adapted to be detachabiy connected with opposing open hooks securedto the door and with which the latch bar has a sliding engagement, andis detachable therefrom.

Among the objects of my invention is t provide a means by which, inclosing the door, the latch bar is automatically locked in its operativeposition to the door against accidental detachment.

A further object of my invention-is o provide a means by which, when thedoor is open, the force resisting its further opening is shifted fromthe hooks and the shank thereof and may be directly to the door, and inthe absence of the possibility of bending or breaking eitherof thehooks.

With these ends in view, my invention finds embodiment in certainfeatures of novcity in the construction, combination. and arrangement ofparts by which the said objects and certain other objects are attained,all as hereinafter fully described with reference to the accompanyingdrawings and more fully pointed out in the claims.

in said drawings,

Fig. 1 is a front elevation showing the automatically locked position ofthe strap on the closing of a door.

Fig. 2 is a section taken on the line 22 of Fig. 1.

Fig. 3 is a. front elevation of the position of the strap relative tothe hooks when the door is open.

Fig. 4 is a vertical section taken on the line l of Fig. 3; and

Fig. 5, a front elevation showing the position of the strap on beingdisconnected from engagement with the hooks therefor.

Similar characters of reference indicate the same parts in the severalfigures of the drawings.

6 indicates a door to which is secured the hook member of my device,which latter that the surface consists of a 31%.t0 7, provided with'longi} tndinal flanges 8' and'a rear end flange 9, which plate, withits flanges, is secured to the door 6 by means of set screws 9, 9, so"

of't'he plate projects ontwardly frcni the door and substantially in aplane with the face 10 of the door frame 11, said pl 5 L being providedwith a slight opening at one side formed by integrally opposing hooks12, 12, bent tl'iere'from with their ends spaced apart, as indicated at13, which plate and the hooks therefor are preferably formed from sheetsteel.

eemed to the edge of the frame of the door and preferably by means ofscrews 14, preferably recessed therein, is a plate15, to which ishinged, by' means of a pintle16, a strap 17, bent upon itself at itsfree end, as indicated at 18, and terminating'in a narrower portion ortongue 19, which tongue is adapted to project through a slot 20 in theplate Z -when the strap is in the position shown inv Fig. 3; that is tosay,.

when the door is wide open as the strap will permit it to be. The strap14, adjacent the hinge, is narrowed, as indicated at 21, suff cientlyfor the passage of the strap between the ends of the hooks 12, but thiscannot be until the door is closed, in order that, as the door begins tomove towards an open position, the wider portion of the strap willprevent its passage between the ends of the hooks.

As indicated by dotted lines 22 in Fig. 4:, the tongue 19 may be ofsutficient length that when the door is open, the bearing of the tonguemay be and is directly against the door, so that, in any attempt toforcibly open the door, that force will be removed in its entirety fromboth the hooks and their shank and be resisted by the door.

My invention also provides, for the first time, so far as I am aware, asimple and effective means for automatically locking the strap againstaccidental detachment from the door when closed, and which, as shown inthe drawings, consists of a catch pawl 23 secured by a pivot 2 1 to theside flanges of the door plate 7, around which is coiled a spring 25,one end of which presses against the catch pawl and the other againstthe plate, for normally maintaining the catch pawl in its lockingposition.

The strap 17 is provided with a slot 26, with which the catch pawl maybe moved against the resistance of the springs to a position registeringtherewith for the detachment of the strap.

From this construction it will now be seen that when the door is closedwith the strap, on being moved to the position shown in Figs. 1 and 2,the catch pawl will yield until it is moved to position registering withthe slot 26, the force of the strap being sufficient to produce thismovement, and so that as soon as the catch pawl is projected through theslot, its spring will move it and lock the strap against accidentaldetachment.

The raising of the flanges of the plate for the pawl provides a meansavoiding the otherwise necessity for swinging the strap to engagementwith the pawl and for the location of the hinge therefor in aplanepermitting the strap to swing to a parallel position against the surfaceof the frame of the door.

Having described my invention, what I claim anddesire to secure byLetters Patent 1s:

1. A safety latch for doors, consisting of a plate secured to the door,provided with an open hooklike slot, the hooks on which are outwardlycurved, a hinged strap secured to the door frame passing through saidslot adapted to be removed therefrom between said projections when thedoor is closed and means projectalole through said strap for locking thedoor.

2. A safety latch for doors, consisting of a plate secured to the door,provided with a slot open at one side, a hinged strap cured to the doorframe passing throng said slot, projecting through said plate andadapted to automatically lock the strap when the door-is in its closedposition and a pawl adapted for locking said strap to the door.

A safety latch for doors, consisting of a plate secured to the door,provided with a slot open at one side, a perforated hinged strap securedto the door frame projecting through said slot, a pawl pivoted to theplate and adapted to register with and be automaticall ro'ected throu hsaid erforation and lock the strap against movement in the slot.

a. A safety latch for doors, comprising a flanged plate located in aplane ith and secured to the surface of the door, and having a slottherein, a pawl pivoted to said plate adapted to be projected throughsaid slot, a strap hinge provided with a slot for opposing said pawl,and means for automatically projecting said pawl through the hinge'slotfor and thereby locking the strap to the plate and door when the latteris in its ALBERT C. DOHRMANN.

